Device for radially deflecting consignments in transport plants

ABSTRACT

A device for radially deflecting consignments in transport plants permits consignments to be conveyed, in linear sections, clamped between an upper belt and a lower belt, where the upper belt urges the inner side of the curvature of the consignments to be conveyed against a surface profile of the deflection device. The deflection device on which the inner side of the curvature of the consignment rests has a surface profile with depressions on the side facing the consignment. The tangential length of the surface profile is at least as long as the outside of the respective consignment.

BACKGROUND OF THE INVENTION

The invention at hand concerns a device for radially deflectingconsignments in transport plants where consignments are conveyed inlinear path segments wedged between an upper and a lower belt.

In letter sorting plants, in particular in address readers, consignmentsup to a specific thickness of 9 mm, for example, are conveyed by meansof an arrangement of cover belts, comprising a lower and an upper belt.Such a transport occurs in particular also in dynamic storage segments,where the consignments are stored mechanically following the addressscanning until the reading result is supplied by the electronic readingequipment and a code corresponding to the reading result is printed ontothe consignment.

A multiple deflection of the cover belt run is necessary, in particularin the storage segments to keep the space requirement low. For this, thecover belt is normally guided over large rollers, wherein the cover beltrun is deflected by 180° or 90°. Such a plant is described in the DE 4437 114.

In known plants, the consignments to be transported are transportedstanding between the upper and the lower belt, wherein the longest sideof the consignment is positioned lengthwise to the transportingdirection. The width of the belts is relatively narrow in relation tothe maximum permissible height of the consignments to be transported(approximately 35 mm for plants with standard letter formats), so thatadditional guide rails are necessary to prevent a buckling of theconsignments.

A further disadvantage of the narrow belts is the occurrence of carbontransfer, which damages carbon-copying papers that are transported inthe consignments in such a way that the recipient cannot utilize theinformation transferred by the sender to the carbon-copying paper. Forthat reason, wider belts are used (approximately 90 mm) to be able totransport the consignments without additional guide rails and to preventor limit carbon transfer.

With the presently known plants, a deformation in radial direction andthus a curvature on the curve inside of the consignment occurs at thedeflection rollers as a result of the radial curvature of the respectiveconsignment through the different radii of curvature for the inside andoutside and the tangential shear restraint of the consignment inside bythe outer edge of the letter.

When the consignment rolls off a deflection roller, this surfacecurvature is pressed directly against the roller or inner belt by thepressure from the outer belt, depending on the type of design. Thisleads to bending folds in the contact pressure area, caused by the outerbelt. With a narrower belt width, these bending folds hardly interfereat all. With a wider belt width, already existing bending folds causedby preceding deflection rollers can cause the consignment to be torn upalong the circulating consignment edge, thus resulting in intolerabledamages. The amount of damage depends on the paper quality, the type offolding of the inserted consignments, the belt running speed, humidityetc. With wide belts, the bending folds continue to occur even in thoseranges where the codes corresponding to the reading result have beenprinted on. As a result of this, the readability of the code can belimited or prevented.

SUMMARY OF THE INVENTION

It is therefore the object of the invention at hand to present a devicewith which the consignments can be deflected without bending folds, evenwith wide belts or rollers, without damaging the consignments orlimiting the readability of the printed-on code. The solution accordingto the invention, is achieved by a device for radially deflectingconsignments in transport plants where an upper belt presses theconsignment to be conveyed with its curvature inside against thedeflection device and the deflection device has as a surface profilewith recesses on the side facing the consignment.

Advantageous embodiments of the invention follow from the dependentclaims and the following description.

The device according to the invention is used on the curve inside. Inthis case, the surface of the device, which faces the consignment has asurface profile with recesses for accepting the curvatures of theconsignments.

The device can be realized in that the surface profile is applieddirectly to a main roller or by surrounding the main roller and apossibly existing secondary roller with a belt having a surface profilewith recesses on the outside. It is particularly advantageous for aprotective treatment of the consignments if the surface profile has awavelike shape and in this case the tangential length of the surfaceprofile on which the respective consignment rests, is at least equal tothe length of the outside of the respective consignment. This isachieved, for example, with a sinusoidal or circular arc surface design.This creates recesses for the curvatures, so that the curvatures are notbent or folded.

The longitudinal section of the surface profile can also be rectangular,triangular or have a saw-tooth shape. It is also possible to providewebs that are positioned perpendicular or diagonal to the transportingdirection, between which the recesses are located. Finally, a surfaceprofile can be used where bumps with a longitudinal cross section withsemicircles to three-quarter circles are applied with a certain spacingto a level surface, between which the recesses are located. The abovelisting is not complete. Any conceivable surface profile with recessesthat run lateral or diagonal to the transporting direction can beselected, wherein wave-shaped surface profiles treat the consignmentsparticularly gently.

The surface profile can be formed perpendicular to the belt movementdirection or also in the range between 45° and 90° to the belt movementdirection. Angles between 70° and 75° have proven to be particularlyadvantageous. The waves can have a sinusoidal or circular arc profile.However, camel hump-shaped waves are also possible. These are realizedin that the height of a sinus or circular arc profile is provided with acircular arc or sinusoidal groove with less depth than the height forthe sinus or circular arc profile.

Furthermore, the wavelike shape of the surface must be realized byarranging nubs with the height necessary for the wavelike shape at ashort distance to each other. Finally, it can be advantageous to providethe wavelike surface profiles with slots or grooves.

A so-called herringbone pattern proves to be particularly advantageous:In this case, two wave-shaped profiles with a specific angle run counterto each other, wherein a groove exists between the wave-shaped profilesfor accepting the folds of the consignments, which come together in thisrange.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in more detail in the following descriptionwith the aid of the figures for the various in which.

FIG. 1 is a portion of the deflection device according to the invention,an upper belt and a consignment located in-between;

FIG. 2 is a main roller with wave-shaped surface profile;

FIG. 3 is a main roller with ring-shaped surface profile, a narrow beltand a secondary roller;

FIG. 4 is a main roller and two secondary rollers over which an elasticbelt with wave-shaped surface profile is guided, as well as an upperbelt, a consignment to be transported and a lower belt;

FIG. 5 is a perspective view of a main roller and a secondary rollerover which an elastic belt with herringbone pattern and groovein-between is guided;

FIG. 6 is a section of a slotted, wave-shaped belt;

FIG. 7 is a section of a belt with wavelike camel hump design;

FIG. 8 is a section of a belt with a rectangular surface profile;

FIG. 9 is a section of a belt with a triangular surface profile;

FIG. 10 is a section of a belt with a saw-tooth shaped surface profile;

FIG. 11 is a section of a belt with fitted on webs and

FIG. 12 is a section of a belt with fitted on three-quarter circles.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows the consignment S, which is pressed by the upper belt Oagainst the inventive deflection device, which in this case is a mainroller H with wave-shaped surface profile P. The profile has a circulararc shape and has recesses V with the height h and the distance a fromwave peak to wave peak. The height h is understood to be the differencebetween radii r₂ and r₁, wherein r₂ represents the distance of the wavepeaks from the mid-point M of main roller H and r₁ the distance of thewave troughs to the mid-point M of the main roller. In order to ensurethat the recesses V for accepting the curvatures of the consignments Sare sufficient, the tangential roll-off area L_(i) of the wave-shapedprofile P, on which the consignment S rests between the points A and E,must be at least as big as the outside length L_(A) of the consignment.This condition is given, for example, with a roller radius r=140 mm, amaximum consignment thickness of 7 mm and a wave distance a=20 mm for aminimum height h=3.1 mm. It is possible, for example, to determine thewave distance a empirically in that the distances between surfacecurvatures on a consignment with maximum dimensions (length, width,thickness) are measured. The surface curvatures are produced by abending of the consignment with the radius r of the main roller H.

These distances then provide the approximate value for a. The exactvalue for a is obtained in that a must be a whole number multiple of thecircumference of the main roller H or the length of the elastic belt EB,so that the continuous wave shape of the wave-shaped surface profile Pis provided.

With the aforementioned dimensions, a recess V with the height h=4 mm isparticularly advantageous. However, it is also possible to use largerrecesses.

The disadvantage of using even larger recesses is the increased materialuse, an increased noise level during the operation and the deterioratingoperating characteristics for elastic belts with wave-shaped profileover the secondary rollers. As a result of the wave-shaped design of thesurface, the surface curvatures can occur on the inside of consignmentS, without folding or bending the consignment. The consignment S thusremains undamaged.

In FIG. 2, the surface profile P is applied directly to the main rollerH. This can be realized in that the roller H and the surface profile areproduced in one piece from the same material. However, it is alsopossible to produce the main roller H cylindrically and to apply thesurface profile P, made from another material such as rubber, Vulkolanor a high-resistance foam. It is also possible to pull a rubber ringprovided with the surface profile P over a cylindrical main roller.

The main roller H advantageously has a radially circulating groove inthe center of its height, which divides the surface profile and forwhich the radius is smaller than the radius r₁ between the wave troughsand the mid-point for main roller H. It is advantageous if a strippingdevice AS engages into this groove in such a way that at the strippingpoint ASP its surface facing the consignment is below the recesseslocated at the stripping point ASP. This stripping device removes theconsignment from the main roller H and forces it onto a linear path. Thestripping device can, for example, consist of a sheet metal piece.

A different stripping device is shown in FIG. 3. In this case as in FIG.2, the main roller itself has a radially circulating groove, wherein forthe example at hand, the groove is provided for accepting the auxiliarybelt HB. The auxiliary belt HB is additionally guided around thesecondary roller N₁.

The groove itself is made deep enough so that the auxiliary belt HB doesnot cause any bends at the consignment S surface curvatures. The mainroller H rotates in the indicated arrow direction.

As soon as the consignment S reaches the area C, the jointly circulatingauxiliary belt HB pushes the consignment S away from the surface profileand into a linear movement direction between the auxiliary belt HB andthe upper belt O.

The inventive device shown in FIG. 4 comprises the cylindrical roller Hzand two secondary rollers N₁ and N₂ across which the elastic belt EBwith surface profile P is stretched. Here too, the consignment S ispressed by the upper belt O against the surface profile P, withoutbending of the surface curvatures. By guiding the elastic belt EB withsurface profile P over the secondary roller N₁, the consignment S ismoved gently from the radial movement direction to the linear movementdirection and, after passing the secondary roller N₁, is later ongripped by the lower belt U and wedged between the upper belt O and thelower belt U where it is transported further in linear direction in thelinear range LB₁. The guiding of the elastic belt EB around thesecondary roller N₂ and the guiding of the lower belt U around theroller I₂ improves the guidance during the intake of the consignment Sfrom the linear range LB₂ into the inventive deflection device.

FIG. 5 shows a view of an inventive device, comprising one main rollerH₂ and a secondary roller N₁, around which an elastic belt EB is guided.The special feature of this elastic belt EB is the shape of thewave-shaped surface profile P_(F). It consists of two mutuallydisplaced, wave-shaped profiles, which respectively occupy an angle ofapproximately 70° to the movement direction and which are separated by agroove NU that runs in the movement direction through the center of theelastic belt EB.

The slanted position of the profiles results in a quieter run of theelastic belt EB, in particular around the secondary roller N₁. Thegroove NU is provided to accept the surface curvatures, which develop onthe consignment inside and run in opposite directions.

FIG. 6 shows a partial section of an elastic belt with slots SC in thewave-shaped profile P, which slots are arranged lateral to thepropagation direction for the waves of the wave-shaped surface profileP. The noise developing during the operation can be reduced with this aswell. FIG. 7 finally shows a profile P_(H) where a circular arc orsinusoidal groove NT with a depth lower than the height h of thecircular arc or sinusoidal profile has been worked into the height of aprofile with circular arc or sinusoidal shape.

FIG. 8 shows a partial segment of an elastic belt with a rectangularsurface profile. The length b of the recess V can be longer than thelength c of the raised portion. The sum of the lengths b+c isapproximately equal to the wave distance a.

FIG. 9 shows a partial section of an elastic belt with a triangularsurface profile. The distance between neighboring triangle pointscorresponds advantageously to the wave distance a.

FIG. 10 shows a partial section of an elastic belt with a saw-toothshaped surface profile. Here too, the distance between neighboringsaw-tooth peaks is advantageously that of the wave distance a.

It is advantageous if the distance of the web ST shown in FIG. 11 to therespectively next web ST also corresponds to the wave distance a.

FIG. 12 finally shows another option for designing the surface profilewith bumps K in the shape of three-quarter circles, between which therecesses V are located.

We claim:
 1. A device for the radial deflection of consignments intransport plants, the consignments being conveyed in linear pathsegments wedged between an upper and a lower belt in a transportingdirection, said radial deflection device comprising a surface profilewith recesses and wherein the upper belt presses an inside curvature ofconsignments to be conveyed against the surface profile of the radialdeflection device.
 2. A device according to claim 1, wherein the surfaceprofile has a rectangular shape.
 3. A device according to claim 1,wherein the surface profile has a saw-tooth design.
 4. A deviceaccording to claim 1, wherein the surface profile has a triangulardesign.
 5. A device according to claim 1, wherein the surface profilehas webs.
 6. A device according to claim 1, wherein the surface profilehas bumps in the shape of a three-quarter circle.
 7. A device accordingto claim 1, wherein the surface profile has slots.
 8. A device accordingto claim 1, wherein the surface profile has a wave-shaped design.
 9. Adevice according to claim 8 characterized in that the wave-shapedsurface profile (P) has a sinusoidal design.
 10. A device according toclaim 8, wherein the wave-shaped surface profile (P) has a circular arcdesign.
 11. A device according to claim 8, wherein the wave-shapedsurface profile is arranged perpendicular to the transporting directionof the consignment.
 12. A device according to claim 9, wherein thewave-shaped surface profile is diagonal to the transporting direction.13. A device according to claim 8, wherein the wave-shaped surfaceprofile is at an angle of more than 45° and less than 90° to thetransporting direction.
 14. A device according to claim 8, wherein thesurface profile is constructed from a foam material.
 15. A deviceaccording to claim 8, wherein the wave-shaped surface profile has atangential length on which the inside curvature of a respectiveconsignment rests, said tangential length being at least equal to theoutside length of the respective consignment which faces the upper belt.16. A device according to claim 1, further comprising a main rollerhaving a mid-point and an outside surface and wherein the surfaceprofile is wave-shaped and the outside surface of the main roller isformed with the wave-shaped surface profile.
 17. A device according toclaim 16, wherein the main roller has a radially, circulating grooveformed in the outside surface, the outside surface being of a height andthe groove being formed in the center of the height of the outsidesurface, the groove having a radius that is smaller than a radiusextending between a wave trough of the surface profile and the mid-pointof the main roller.
 18. A device according to claim 17, furthercomprising a stripping device which engages the groove for removing theconsignment from the main roller and forcing the consignment onto alinear path.
 19. A device according to claim 17, further comprising anauxiliary belt and a secondary roller wherein the auxiliary belt isguided in the radially circulating groove and over at least onesecondary roller.
 20. A device according to claim 1, further comprisinga main roller, at least one secondary roller, all of the rollers havinga cylindrical design, and an elastic belt which is guided around themain roller and the at least one secondary roller wherein the elasticbelt has the surface profile which is wave-shaped and formed on the sideof the belt which faces away from the main roller and the at least onesecondary roller.